The lawsuits center on laws Republicans approved in December to weaken the authority of Gov. Tony Evers and Attorney General Josh Kaul. They approved the laws after the two Democrats won their elections but before they were sworn in.

The case at issue in Monday's order was brought by the League of Women Voters of Wisconsin, Black Leaders Organizing for Communities and Disability Rights Wisconsin.

They contend all actions from the lame-duck session are unconstitutional because of the method Republican lawmakers used to get themselves to the floor of the Assembly and Senate.

Lawmakers called themselves into what's known as an extraordinary session, a process they have used to gather in Madison at times when they weren't scheduled to take votes. They've called extraordinary sessions from time to time for nearly 40 years.

The groups argue such sessions aren't allowed because the state constitution says lawmakers can meet only when called into a special session by the governor or as "provided by law." State law does not explicitly allow extraordinary sessions.

Legislators say they had the right to call the session and warn that hundreds of other laws could be tossed aside if courts determine extraordinary sessions aren't allowed.

Dane County Circuit Judge Richard Niess in March said those bringing the lawsuit were likely to succeed. He invalidated the lame-duck laws, as well as the confirmations of 82 appointments by former Gov. Scott Walker that were approved during the lame-duck session.

In response, Evers revoked the appointments of the 82 officials. (He later reinstated 67 of the Walker appointees but left the other 15 positions vacant.)

The District 3 Court of Appeals reversed Niess' decision and reinstated the lame-duck laws. But in a separate decision, the appeals court upheld Evers' ability to sideline the Walker appointees.

Now, the Supreme Court can decide whether the lame-duck laws are acceptable and whether the 15 Walker appointees should get their positions back.

The move comes as the 4-3 conservative majority on the high court is about to expand to 5-2.

Liberal Justice Shirley Abrahamson did not run for re-election this month and conservative Judge Brian Hagedorn won the race to replace her. He will be seated in August.

With arguments in May, the Supreme Court could decide the case before Hagedorn joins the court.

Three other cases have been filed. In one, a federal judge blocked early voting limits included in the lame-duck laws.

In another, Dane County Circuit Judge Frank Remington invalidated some of the lame-duck laws while he considers the case. That ruling is on appeal.

In the third case, U.S. District Judge James Peterson last week asked both sides to file briefs on whether he should pause the case he is considering while state courts handle litigation over the laws.

Contact Patrick Marley at patrick.marley@jrn.com. Follow him on Twitter at @patrickdmarley.